Drain valve

ABSTRACT

A drain valve allows for drainage of fluids while preventing backflow of gases from a drainage system through the drain valve. A drain valve can have a first, sealed position in which a component of the valve seals an opening through the valve and a second, open position in which the component of the valve is separated from the opening to allow a fluid to drain through the valve. When the fluid has drained through, the component of the valve can return to the closed position. The valve can include a pressure relief conduit to help equalize pressure across the valve and permit unrestrained draining of fluid through the valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication, are hereby incorporated by reference in their entiretyunder 37 CFR 1.57.

BACKGROUND

1. Field of the Disclosure

The present disclosure relates in general to valves for floor drains,such as valves useful in drains for buildings, floors, basements,exterior paved areas or other areas that require drainage, as well asfor urinals and other waste handling devices connected to a sewer ordrain conduit.

2. Description of the Related Art

Floor drains are frequently used with a trap that catches a volume ofwater in such a way that direct access for gas from the drain system tothe area above the floor drain is blocked but that allows passage of thewater. Floor drains are available in many shapes and are used in laundryrooms, bathrooms, shower spaces etc. for the draining of water.Traditionally, U-shaped or “gooseneck” traps have been used in theplumbing industry to prevent backflow of harmful or undesirable sewer orpipe gases into buildings while permitting drainage of unwanted liquidfrom floors and other generally horizontal surfaces. Such traps operateby leaving a small quantity of fluid within the lower portion of aU-shaped trap section to act as a gas barrier. In many applications,however, particularly where access is difficult or where drainage isinfrequent, gooseneck traps are not optimal due to insufficient space toinstall and to inaccessability. Fluid in gooseneck trap may evaporatefrom the trap, permitting free flow of obnoxious gasses through thedrain, insects may breed in the fluid, or in some instances the fluidsmay harden so as to actually block or restrict flow through the drain.

Drains with barrier seals have been developed to overcome some of theshortcomings of the gooseneck traps. However, barrier seal type valveswith further improvement in their effectiveness, manufacturability,reliability, and ease of use are desirable.

SUMMARY OF THE DISCLOSURE

Various drain valve embodiments described herein are configured toprovide a drain valve that prevents or substantially prevents thebackflow of large quantities of gases from the drain or sewer whilepermitting liquids to flow downwardly into the drain or sewer.

Other drain valve embodiments described herein are configured to providea drain valve that permit equalization of pressure above and below thevalve flapper so that even small quantities of water upon the uppersurface of the flapper will cause it to open and drain.

Other drain valve embodiments described herein are configured to providea drain valve that includes a pressure equalization conduit with a ballvalve, said conduit extending from below to above the flapper, the ballvalve structure being used to close the pressure relieving conduit forpressure testing of the drain or sewer below the valve.

Other drain valve embodiments described herein are configured to provideimproved effectiveness, manufacturability, simplicity and reliabilityfor drain valves used in draining floor surfaces and the like.

Other drain valve embodiments described herein are configured to providea valve housing having the upper portion thereof formed to permitexpansion outwardly into engagement with the interior of the floor drainhousing to secure the valve housing in place and prevent elevatedpressures beneath the valve housing from dislodging the valve housingfrom its operative position.

To minimize the limitations found in the prior art, and to minimizeother limitations that will be apparent upon the reading of thespecifications, one preferred embodiment of the present disclosureprovides a valve used in drains for building floors, basements, andexterior paved areas to permit backflow of small amounts of backflowgases to prevent excess pressure on the bottom side of a drain valveflapper. In a second embodiment, the valve may close and preventbackflow of fluids in both normal operations and in pressure testing ofthe downstream drain conduit. To prevent the valve structure from beingforced upwardly by pressure below the valve a securing and sealingsystem such as a rotatable ring threaded to expand the upper zone of thevalve body into contact with the inner wall of a drain conduit isprovided to cause the upper portion of the drain valve body to beexpanded into secure frictional engagement with the drain housing inwhich the valve is installed. Other means to hold the valve body inplace are contemplated as well. A gasket surrounding the drain valvebody is provided to securely seal the drain valve body with in the drainhousing. The drain valve of this invention provides a drain valve thatpermits conduct of pressure testing of downstream conduits without thesubsequent removal of the solid plug used for pressure testing. Thedrain valve permits equalization of pressure above and below the flapperwhen the valve is used for subsequent drainage of the floor or otherarea. Finally, the drain valve would provide improved effectiveness,manufacturability, simplicity and reliability

Various embodiments of drain valves described herein can include checkvalves that allow for drainage of fluids while preventing backflow offluids (including gases) from a drainage system through the drain valve.In some embodiments, a check valve can have a first, sealed position inwhich a component of the check valve seals an opening through the valveand a second, open position in which the component of the check valve(such as a flapper) is separated from the opening to allow a fluid todrain through the valve. When the fluid has drained through, thecomponent of the valve can return to the closed position. In someembodiments, the valve can be configured to resist back pressure in thesystem, such as during storm events or to allow for back pressuretesting of the drain system downstream of the valve for leaks and otheranomalies. Thus, back pressure testing can occur without having toremove the valve and block the drain with a separate device, as istypically done.

In some embodiments, the valve can include a closure, very light inweight, positioned at the top of the conduit connecting a zone below theflapper with a zone above the flapper. The closure is raised by a verysmall amount of pressure and permits gas to flow from the area below theflapper to the area above the flapper. This embodiment is generally usedin situations where the back pressure needs to be equalized across theflapper so that the flapper will open whenever water, even in smallquantities, flows into the valve. In some embodiments, the valve may notprovide the capability of back pressure testing, such as for testing thesewer or pipe below the valve.

In some embodiments, the valve can be functionally similar to the priordescribed embodiment, but can incorporate a ball valve at the bottom ofthe conduit. The ball valve may be closed by the presence of water (orsubstantial gas flow) flowing backward, such as from the water filled “Ptrap” used in drain or sewer systems. The ball valve, which ispositioned below the flapper in the conduit, can connect the zone of thevalve structure below the flapper with the zone of the valve structureof the flapper so that the valve may be sealed to back pressure, therebypermitting pressure testing of the sewer or piping below the valve. Itmay not be necessary to remove the ball valve structure after theinstallation of the flapper valve, since it can operate in the samefashion as the prior described embodiments so long as the ball is notraised by the presence of water below the flapper.

The drain valve flapper includes an elastomeric hinge that connects themounting structure with the flapper. The elastomeric hinge urges theflapper into normally closed position against flapper seat whilepermitting the flapper to open when the water flows down on the uppersurface of the flapper. The flapper is positioned, using a keeper whichis preferably removable, in a flapper mount. The flapper mount ispositioned at an angle to bias the elastomeric hinge upwardly so thatthe flapper is held against the flapper seat when at rest withoutdownwardly moving water. The flapper mount preferably holds the flapperat an angle relative to the horizontal.

The drain valve of this invention may utilize and expansion device suchas a securing and sealing ring preferably at the upper portion of thevalve body to secure the valve body in operative position within thedrain conduit. An alternative securing and sealing structurecontemplated herein is a gasket structure having an inflatable voidextending partially or completely around the outer wall of the valvebody. Inflation of the gasket structure would force the periphery of thegasket into a secure sealing against the interior of the drain conduitand would prevent the valve body from being dislodged whenever pressureis applied in the conduit downstream of the valve body.

In certain conditions of operation, back pressure in the system mayhinder the opening of a check valve. In some embodiments, it can bedesirable to provide some form of pressure equalization in order topermit unrestricted opening of the valve. Such a form of pressureequalization can, during normal operation or the check valve, helpequalize pressure across the valve (e.g., equalize pressure on bothsides of a valve flapper) when necessary but still prevent backflow ofundesirable gases once the pressure has been equalized. By helpingequalize pressure, normal operation of the check valve can be ensured.Additionally, equalizing pressure can ensure that the check valve canopen at pressures consistent with regulatory standards.

In some embodiments, inclusion of a pressure equalization system canallow backflow of fluids in addition to allowing for the release ofgases needed to equalize pressure. Thus, in some embodiments, where asystem design is desired to include prevention of backflow during highpressure events, such as to perform back pressure testing, a drain valvecan include a pressure equalization valve or system and also include anadditional valve to block backflow during high pressure events.

In some embodiments, to prevent a drain valve structure from beingforced upwardly by pressure below the valve a securing and sealingsystem such as a rotatable ring threaded to expand the upper zone of thevalve body into contact with the inner wall of a drain conduit isprovided. The ring can cause the upper portion of the drain valve bodyto be expanded into secure frictional engagement with the drain housingin which the valve is installed. Other means to hold the valve body inplace are contemplated as well. In some embodiments, a gasketsurrounding the drain valve body is provided to securely seal the drainvalve body within a drain housing.

In some embodiments, a drain valve allows for the equalization ofpressure above and below the flapper of a check valve without providingthe ability to block backflow of high pressures to thereby allow forpressure testing the sewer or pipe below the valve. The drain valve caninclude a light weight closure positioned in a pressure relief conduitconnecting a zone below the flapper with a zone above the flapper. Theclosure can be raised by a very small amount of pressure and permit gasto flow from the area below the flapper to the area above the flapper.Such embodiments are generally used in situations in which the backpressure needs to be equalized across the flapper so that the flapperwill open whenever fluid, even in small quantities, flows into the drainvalve.

In some embodiments, a drain valve can prevent fluid backflow duringnormal conditions and during high pressure conditions, such as whentesting back pressure in the system. In some embodiments, the drainvalve can have just a flapper that operates as a check valve to permitfluid to flow through the valve in a first direction but not in anopposing direction. In some embodiments, the drain valve can have apressure relief and also an additional valve to prevent fluid backflowduring normal operating conditions and to permit pressure testing of thedrain or sewer system beneath the drain valve. The additional valve canbe, for example, a ball valve with a lightweight closure that houses aball. The ball valve can be positioned in the pressure relief conduitand can be closed by the presence of a strong backflow pressure. Theball valve can connect the zone of the valve structure below the flapperwith the zone of the valve structure above the flapper so that the valvemay be sealed against high back pressures, thereby permitting pressuretesting of the sewer or piping below the valve. At low back pressures,the ball valve can remain open and allow for pressure equalization.

In some embodiments, a drain valve flapper can include an elastomerichinge that connects a mounting structure with the flapper. Theelastomeric hinge can urge the flapper into a normally closed positionagainst a flapper seat while permitting the flapper to open when fluidflows onto the upper surface of the flapper. The flapper can be securedto the flapper mount using a mounting bracket or clip. The flapper canbe mounted at an angle to bias the elastomeric hinge upwardly so thatthe flapper is held against the flapper seat when at rest withoutdownwardly moving water. The flapper mount preferably holds the flapperat an angle relative to the horizontal.

Various embodiments described herein may utilize an expansion device,such as a securing and sealing ring, to help secure the valve body in anoperative position within the drain conduit. In some embodiments, adrain valve can include a gasket structure having an inflatable membraneextending partially or completely around the outer wall of the valvebody. Inflation of the gasket structure can force the periphery of themembrane into a secure sealing position against the interior of thedrain conduit and can prevent the valve body from being dislodgedwhenever pressure is applied in the conduit downstream of the valvebody.

In some embodiments, preferred securing and sealing ring can be adaptedfor rotational installation in which a threaded exterior of the sealingring engages and expands the upper portion of the valve body. The upperportion may be formed of elastomeric material or alternatively the rigidvalve body may have the upper portion thereof slotted to permit outwardexpansion thereof into secure engagement with the drain conduit. Thissecure engagement with the floor drain housing prevents pressure beneaththe valve body from ejecting the valve body upwardly from the floordrain housing.

In some embodiments, a securing and sealing ring can incorporate atapered threaded portion which engages a threaded portion of the valvebody to cause an upper portion of the valve body to expand when the ringis rotated. The securing and sealing means may be incorporated into thevalve body exterior or may be a securing and sealing device which isseparately placed into the drain conduit in structural contact with thevalve body.

The preferred securing and sealing ring is adapted for rotationalinstallation in which a threaded exterior of the sealing ring engagesand expands the upper portion of the valve body. The upper portion maybe formed of elastomeric material or alternatively the rigid valve bodymay have the upper portion thereof slotted to permit outward expansionthereof into secure engagement with the drain conduit. This secureengagement with the floor drain housing prevents pressure beneath thevalve body from ejecting the valve body upwardly from the floor drainhousing.

The securing and sealing ring utilizes a tapered threaded portion whichengages the threaded portion of the valve body to cause the upperportion of the valve body to expand when the ring is rotated. Thepresent invention provides a method of draining a floor or other area,which includes a pressure testing configuration, by preventing thebackflow of fluid (gas or liquid) under pressure thereby permittingpressure testing of the conduit downstream of the drain valve. Thesecuring and sealing means may be incorporated into the valve bodyexterior or may be a securing and sealing device which is separatelyplaced into the drain conduit in structural contact with the valve body.

The present disclosure also provides a method of draining a floor whilepreventing the backflow of gas under pressure thereby permittingpressure testing of the conduit downstream of the valve. The methodaccording to one embodiment includes the step of positioning a flapperwithin a cylindrical body such that a peripheral edge of the rigidflapper adjacent an inlet of the cylindrical body is resiliently andflexibly attached to the cylindrical body by a resilient hinge having anindexing embossment fitting into an indexing groove for positiveplacement of the flapper. The indexing embossment also serves todistribute forces exerted by back pressure upon the flapper therebymaintaining the flapper in its position when sealed against a valveseat. A peripheral edge of the rigid flapper adjacent the outlet of thecylindrical body is urged into sealing relationship with a sealingsurface on a valve seat but is free to deflect towards the outlet toopen the valve permitting downward flow of liquids therethrough. Inaddition the valve configuration is adapted to resist back pressure fromthe drain so that the drain may be tested for leakage. The features ofthe present disclosure are described in greater detail below.

In various embodiments, a check valve can include a cylindrical body,including an inlet end and an opposed outlet end; a resilient flappermount connected to an inside surface of the cylindrical body, saidflapper mount having an indexing groove extending across a substantialportion of said mount; a flapper stop positioned on the inside surfaceof the cylindrical body between the flapper mount and the outlet end ofthe cylindrical body; and a flapper connected to said flapper mount,said flapper having a mounting flange with an indexing ridge forinsertion into said indexing groove, said flapper being rotatable uponan elastomeric hinge from a first closed position engaged with theflapper stop to allow liquid that enters the inlet to exit the checkvalve through the outlet and when in the closed position preventsbackflow of gases.

In various embodiments, a check valve assembly can include a drain basinconfigured to be inserted into a floor, the drain basin including anupper end and a lower end, wherein the area of the upper end is greaterthan the area of the lower end. The assembly can include a check valveconfigured to be secured between the upper and lower ends of the drainbasin, the check valve being configured to be inserted and removed fromthe drain basin from the upper end of the drain basin. In someembodiments, the check valve can including a cylindrical body, includingan inlet end and an opposed outlet end, a flapper seat, and a relativelyrigid flapper having a mounting tab with indexing ridge and resilienthinge. The flapper can be mounted upon the flapper mount and positionedwithin the cylindrical body at an angle and urged into sealing contactwith the seat by the resilient hinge. A portion of an upper peripheryedge of the flapper can be connected to the cylindrical body, and aportion of a lower peripheral edge can be configured to deflect to allowfluid to pass through the cylindrical body of the check valve. Liquidsmay pass downwardly through the check valve and gases from below thecheck valve are prevented from upward movement.

In various embodiments, a floor drain valve can include a substantiallycylindrical outer housing configured to fit within a drain conduit, anda substantially cylindrical inner housing connected with the outerhousing. The valve can include a flapper seat having an apertureconnected to an inner surface of the inner housing, a flapper positionedat the aperture, and a flapper mount having an aperture configured toreceive an alignment pin and hold the flapper against the flapper seat.A conduit can attach to the inner housing and extend from an area belowthe flapper to an area above the flapper. A closure can be positioned atthe top of the conduit, the closer being raised under pressure to permitgas to flow from the area below the flapper to the area above theflapper. A shield can connect to the inner housing and be adapted tocover the closure. An elastomeric hinge can connect the shield with theflapper seat and allow the flapper to pivot, thereby allowing fluid topass through the inner housing. The closure can also be configured toprovide equalization of pressure above and below the flapper to therebyallow the flapper to open when fluid flows into the valve.

In various embodiments, a floor drain valve can include a drain valvehousing configured to fit within a drain conduit, the drain valvehousing including an inlet, an outlet, and a valve seat. A flapper canbe mounted within the housing and have a first side facing a first sideof the valve and a second side facing a second side of the valve, theflapper biased toward a closed position in which the first side of asealing portion of the flapper engages with the valve seat to therebyblock at least a portion of backflow through the drain housing. Theflapper can also be configured such that a pressure on the first side ofthe flapper moves the flapper to an open position in which fluid canflow past the flapper. The drain valve can also include a pressureequalization conduit fluidly connecting a first side of the drain valveon the first side of the flapper with a second side of the drain valveon the second side of the flapper. A valve member can be within thepressure equalization conduit, the valve member configured to move froma closed position that substantially blocks fluid transfer between thefirst and second sides of the drain valve to an open position when apressure on the second side of the drain valve exceeds a first definedpressure, thereby allowing the pressure on the second side of the drainvalve to bleed into the first side of the drain valve.

In various embodiments, a floor drain valve can include a drain valvehousing having an inlet and an outlet; a one way valve positioned withinthe drain valve housing, the one way valve configured to restrictbackflow through the drain housing while allowing fluid to drain throughthe drain housing from the inlet to the outlet in a first direction; apressure equalization conduit fluidly connecting a first side of the oneway valve a second side of one way valve; and a valve member configuredto move from a closed position that restricts fluid transfer between thefirst and second sides of the one way valve to an open position when apressure on the second side of the one way valve exceeds a first definedpressure, thereby allowing the pressure on the second side of the oneway valve to bleed into the first side of the one way valve.

In various embodiments, a floor drain valve can include a drain valvehousing configured to fit within a drain conduit, the drain valvehousing including an inlet, an outlet, a valve seat, and a flapper mounthaving an indexing indentation. The flapper can include a sealingsection, an attachment section, and a resilient hinge between thesealing section and the attachment section. The attachment section caninclude an indexing protrusion configured to couple with the indexingindentation to thereby align the flapper such that the sealing sectionengages the valve seat when the flapper is in a closed position tosubstantially prevent backflow of fluids through the drain valve. Theresilient hinge can bias the flapper toward the closed position, and thehinge can be configured such that a fluid passing through the inlet andapplying a pressure on the flapper moves the flapper from the closedposition to an open position in which the fluid can pass by the flapperand through the outlet.

In various embodiments, an expandable floor drain valve assembly caninclude a drain valve housing configured to fit within a drain conduit,the drain valve housing including an upper section defining an inlet,and a lower section defining an outlet. The upper section can include aplurality of flexible panels separated by slits, and at least a portionof the flexible panels can have internal threading. A valve member canbe positioned within the drain valve housing and can be configured toallow fluid to flow through the drain valve housing from the inlet tothe outlet but substantially block fluid from flowing through the drainvalve housing from the outlet to the inlet. The assembly can alsoinclude an expansion ring having external threading, the expansion ringconfigured to be screwed into the upper section of the drain valvehousing and to drive the flexible panels outward into engagement withthe drain conduit as the expansion ring is screwed into the uppersection to thereby tighten the drain valve within the drain conduit.

In various embodiments, a method of installing a drain valve into adrain conduit having a strainer mount can include providing a drainvalve have a valve body and a flexible exterior gasket, wherein thegasket in an equilibrium position has a width greater than an innerdiameter of the strainer mount and the valve body has a width smallerthan the inner diameter of the strainer mount; deforming the gasket intoa configuration sized to fit through the strainer mount of the drainconduit; inserting the gasket through the strainer mount and into saidconduit; inserting the valve body through the strainer mount;positioning the valve body in the gasket; and positioning the valve bodyand gasket into an operational position within the drain conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

Elements in the figures have not necessarily been drawn to scale inorder to enhance their clarity and improve understanding of thesevarious elements and embodiments described herein. Furthermore, elementsthat are known to be common and well understood to those in the industryare not depicted in order to provide a clear view of the variousembodiments described herein, thus the drawings are generalized in formin the interest of clarity and conciseness.

FIG. 1 illustrates a top perspective view of one embodiment of a drainvalve;

FIG. 2 illustrates a bottom perspective view of the drain valve of FIG.1;

FIG. 3 illustrates a cross sectional view of one embodiment of a drainvalve with a pressure relief conduit;

FIG. 4 illustrates a cross sectional view of one embodiment of a drainvalve with a pressure relief conduit and a backflow valve;

FIG. 5 is an exploded perspective view of the drain valve of FIG. 5;

FIGS. 6A-6C are different views of one embodiment of a flapper;

FIGS. 7A-7C are different views of one embodiment of a flapper;

FIG. 8 is a bottom perspective view of a housing used with a drainvalve;

FIG. 9A is a top perspective view of a bushing with an insertion tool;

FIG. 9B is a top perspective view of the bushing of FIG. 10A without theinsertion tool;

FIG. 10A illustrates a cross sectional view of one embodiment of a drainvalve with a pressure relief conduit and a backflow valve;

FIG. 10B illustrates a cross section of a portion of a gasket.

FIG. 11 illustrates a cross section of a portion of a gasket.

DETAILED DESCRIPTION

In the following discussion that addresses a number of embodiments andapplications, reference is made to the accompanying drawings that form apart hereof, and in which is shown by way of illustration specificembodiments in which the embodiments described herein may be practiced.It is to be understood that other embodiments may be utilized andchanges may be made without departing from the scope of the disclosure.

Various inventive features are described below that can each be usedindependently of one another or in combination with other features.However, any single inventive feature may not address all of theproblems discussed above or only address one of the problems discussedabove. Further, one or more of the problems discussed above may not befully addressed by the features of each embodiment described below.

Referring to FIG. 1 and FIG. 2, a first embodiment of the floor drainvalve 10 of the present disclosure is described. The floor drain valve10 can include a gasket 12 configured to fit into a sealing relationshipin a drain conduit and a housing 14 positioned within the gasket 12. Insome embodiments, the housing can be generally cylindrical. In someembodiments, the housing can have an internal diameter that is wider atthe top (e.g., at the inlet) than at the bottom (e.g., at the outlet).In some embodiments, the housing can have a generally constant internaldiameter. The housing can include a flapper seat 18 (see also FIG. 3)that is connected to or formed as a part of housing 14. A one-way valve,such as a valve using a membrane or flapper 16, can be positioned withinthe housing and can be configured to engage and seal against the flapperseat 18 to prevent passage of fluids through the housing. In someembodiments, described further below, a flapper 16 can include one ormore ridges, ribs, or other structures 19 to increase the structuralstability of the flapper.

With reference to FIG. 2, a flapper 16 can attach to a flapper mount(illustrated and described in more detail below) that can include one ormore mounting projections 37 to help align the flapper 16. In someembodiments, a mounting clip 23 can be positioned to secure the flapper16 in position. The flapper 16 is preferably biased upward into a closedposition against a lower surface of the flapper seat 18. In someembodiments, the flapper 16 can include a resilient, elastomeric hinge(described and illustrated below) that can help bias the flapper 16 intothe closed position. In the closed position, the flapper can resist orblock backflow of fluid. Sufficient pressure above the flapper 16 canmove the flapper 16 into an open position in which the flapper isseparated or partially separated from the flapper seat 18, therebyallowing fluid to pass through the housing 14 and past the flapper 16.In some embodiments, the flapper in the open position may have only aportion of the flapper separated from the flapper seat. A pressure belowthe flapper will tend to push the flapper more firmly against theflapper seat 18, further sealing the flapper against the seat andfurther restricting or blocking passage of fluid past the flapper.Generally, unless noted to the contrary, discussions of pressures on oneside or another of the valve 10, the flapper 16, or other componentrefers to a net pressure or force.

Preferably, a minimal downward pressure is required to open the flapperand permit a downward flow of fluid into the drain conduit 60. In someembodiments, 100 grams of fluid on the flapper can provide the minimumamount of force needed to move the flapper to an open position. In someembodiments, 25 grams, 50 grams, or 75 grams of fluid on the flapper canprovide the minimum amount of force needed to move the flapper to anopen position.

In some embodiments, too much pressure below the flapper may not bedesirable. Because greater pressure seals the flapper 16 more tightlyagainst the flapper seat 18, it can require a greater pressure above theflapper to cause the flapper to open and allow fluid to drain. Thus, insome embodiments it may be desirable to allow for pressure thataccumulates in a drainage or plumbing system and against a bottom sideof the flapper to release. In some embodiments, a floor drain valve 10can include a pressure relief conduit 34 extending from an area belowthe flapper 16 to an area above the flapper. The fluid relief conduitcan allow for equalization of pressures on either side of the flapper,such that the amount of pressure above the flapper required for it toopen remains generally constant. This is described in more detail below.

FIG. 3 illustrates one embodiment of a floor drain valve 10 thatincludes a pressure relief conduit 34. In some embodiments, asillustrated, the pressure relief conduit can be included as part of thehousing 14 and can be offset from the flapper. In some embodiments, thepressure relief conduit can be included as part of the flapper and/orpass directly through the flapper. In such embodiments, the valve can becarried by the flapper. Preferably, a valve is included within thepressure relief conduit 34. This can help ensure that odors or othergases below the flapper valve 16 do not regularly mix with gases abovethe flapper valve 16, and that fluids only flow through the pressurerelief conduit from below the flapper to above the flapper when there isa sufficient desired pressure differential.

In various embodiments, different types of valves and valve actuationsystems can be used. In the illustrated embodiment of FIG. 3, thepressure relief conduit 34 can include a valve member 30 that is biasedinto a closed position by gravity. When the valve member is in a closedposition it can restrict or block passage of fluid past the valvemember. When a sufficient pressure accumulates below the flapper, thevalve member 30 can be raised by the pressure, permitting an amount ofgas to flow from the area below the flapper 16 to the area above theflapper until the pressure drops sufficiently for the valve member tofall back down and seal. The valve member 30 can be sized and configuredto open at different pressures. In some embodiments, it can beconfigured to open at minimal pressure to help ensure that the regionabove the flapper 16 is generally in equilibrium with the region belowthe flapper. In some embodiments, the valve member 30 can be configuredto open at a defined pressure differential greater than zero. Othertypes of valves that can be used include electronically or mechanical orotherwise actuated valves that open and/or close when a pressure sensordetermines a defined pressure below the flapper 16 and/or other types ofmechanical one way valves such as, for example, ball valves, checkvalves, flapper valves, slit valves, duckbill valves etc.

In some embodiments, a shield 20 can be positioned to cover the pressurerelief conduit 34. In some embodiments, the shield 20 can be connectedto the housing 14. The shield 20 can be used to prevent liquid thatflows into the housing from flowing into the relief conduit 34 and/oronto the valve member 30. This can keep the relief conduit full of air,which can help ensure that the valve member 30 can open as necessary. Itcan also generally protect the valve member 30 and the conduit 34 from adownward flow of liquid and debris whenever the flapper 16 is opened bythe presence of liquid above the flapper 16.

With further reference to FIG. 3, the drain valve 10 is illustrated in aposition to be installed into a drain conduit 60. A gasket 12 around thehousing 14 of the drain valve can be configured to help orient and/orseal the drain valve with the drain conduit. For example, in someembodiments the gasket can include an upper flange 15 that has a lowersurface 13 configured to engage an upper surface 62 of the drain conduitto help seat the drain valve 10 in the drain conduit. In someembodiments, the gasket can include one or more sealing projections 31.The diameter of the gasket at one or more of the sealing projections canbe configured to be wider than a diameter of the drain conduit 60, suchthat as the drain valve 10 is thrust downwardly into the drain conduit60 the sealing projections will deflect upwardly and apply a lateralpressure against the drain conduit to help seat and/or seal the drainvalve in position. In some embodiments, a gasket can have multiplesealing projections of varying length to help ensure that the gasket canfit and seal within various drain conduit configurations encountered inthe field. In some embodiments, in addition to or instead of sealingprojections, a gasket can include an inflatable structure on an exteriorof the gasket that can be inflated to secure the gasket in position.This is illustrated and described in FIG. 11, below.

In some embodiments, the gasket 12 and housing 14 can be installedseparately. For example, in some instances, the drain conduit into whicha drain valve is to be installed can include a permanently installedstrainer mount having an inside diameter that is too small for thegasket to fit through. In such instances, the drain valve may beinstalled by separating the gasket 12 from the housing 14. The gasket 12can be compressed into an oval shape or other narrowing shape, insertedthrough the strainer mount (once the strainer has been removed) andplaced into its operative position within the drain conduit. The housing14 can then be inserted through the strainer mount into engagement withthe gasket 12 in its operative position within the drain conduit. Thestrainer can then be returned into position within the strainer mount.This method permits installation of drain valves into drain systems forwhich the drain valve otherwise would not have been able to be used.

Other installation methods and structures are considered. For example,in some embodiments, rather than or in addition to using a gasket, anouter housing or shell can be installed in a drain conduit and the drainvalve 10 can be inserted into the outer housing or shell. In someembodiments, the outer housing or shell can be glued or screwed into thedrain valve. In some embodiments, the outer housing or shell can haveinternal threading and the housing 14 of the drain valve can haveexternal threading configured to mate with the threading of the outerhousing or shell. In some embodiments, the outer housing or shell can besized and configured to sealingly retain the drain valve housing 14without a threaded connection.

In some embodiments, it can be desirable to provide a valve in thepressure relief conduit 34 that closes when a pressure differentialbetween the area above the flapper 16 and below the flapper exceeds acertain value. This can be useful, for example, where a sewer system istied to a storm system. In such instances, during a storm event thatfloods the storm and sewer systems, high pressure fluids could bypassthe flapper valve and flow up through the pressure relief conduit. Avalve that closes when a pressure differential exceeds a certain valuecan also be useful in allowing for back pressure testing, such as ofdownstream drain conduits, without having fluids flow up through thepressure relief conduit 34 and without having to remove the valve andinsert a plug.

In some embodiments, a ball valve 24 can be used to preventhigh-pressure flows from passing upward through the pressure reliefvalve. FIG. 4 illustrates a cross sectional view of one embodiment of afloor drain valve 10 that includes a ball valve 24 in the pressurerelief conduit 34. The ball valve 24 can include a ball valve seat 32 atan upper end of the ball valve and a ball retainer 26 positioned at thebottom of the conduit, below the flapper. In some embodiments, the ballretainer can be part of a mounting clip as described herein. The ballretainer 26 is designed to retain a ball 27. The ball valve asillustrated is in an open position that allows fluid to flow past theball. When the ball valve 24 experiences a pressure beneath the valve,the pressure can drive the ball upward into sealing engagement with theball valve seat 32 and into a closed position, thereby restricting orblocking passage of fluids through the pressure relief conduit. In someembodiments, the ball 27 can be configured to float, such that it risesin water. Thus, in some embodiments, when the ball valve 24 experiencesa pressure beneath the valve or a rise of liquid, the pressure or liquidcan drive the ball upward into sealing engagement with the ball valveseat 32, thereby blocking or substantially blocking passage of fluidsthrough the pressure relief conduit.

In some embodiments, as illustrated, a ball valve can be used with avalve member 30 to both allow for equalization of pressure on oppositesides of the flapper 60 and to stop backflow during high pressureevents. In some embodiments, a single valve can be used to allow forpressure equalization and to stop upward flow during high pressureevents. For example, in some embodiments a ball valve can be configuredto close during high flow events, as described above, but can also beconfigured to seal against a ball valve seat at a lower end of the ballvalve when no pressure differential exists, such that the ball valve isonly open during a range of pressure differentials between the areaabove the flapper 16 and the area below the flapper.

FIG. 4 also illustrates an embodiment of a floor drain valve 10 in whichthe valve includes an expansion ring, such as a bushing 84, that can beused to expand the housing into tightened engagement with a drain. Thisis described in more detail below.

FIG. 4 also illustrates an embodiment of a floor drain valve 10 in whicha housing 14 extends below the gasket 12. In some embodiments, thehousing 14 can have a generally tapered outer profile to help preventthe valve 10 from becoming lodged within the drain 60. In someembodiments, a housing can be elongated to provide room for a pressurerelief conduit 34 with a ball valve or to provide an extended lengthpressure relief conduit.

In some embodiments, a gasket and housing can include featuresconfigured to help position and/or seal the gasket in the housing toprevent fluid from passing between the two. For example, in someembodiments, a housing can have a cutout that receives a correspondingprotrusion of the gasket, or a housing can have a ledge, such asillustrated in FIG. 4, a downward facing ledge 28 on its outer surfacethat can be configured to receive a section of a gasket 12, such as alower flange or shelf 79, to help position the gasket around the housing14. In some embodiments, a gasket can include an O-ring 77, which can bea separate component or integrally molded with the gasket. The O-ringcan help provide a seal between the gasket and the housing 14.Additionally, insertion of the gasket into a floor drain conduit 60 canfrequently place an upward force on the gasket, which can furtherimprove the seal between the gasket and the housing. In someembodiments, the O-ring can be configured to at least partially fitwithin a corresponding channel in the downward facing ledge 28 of thehousing 14.

FIG. 5 is an exploded view of the floor drain valve 10 of FIG. 4. FIG. 5helps illustrate how many of the components of a valve can be aligned.For example, in some embodiments the housing 14 can include a separableupper portion 82 and a lower portion 82. A lower portion 82 can includea mount 36 configured to receive an attachment portion of a flapper 16(described in more detail below). A support plate or clip 23 can beconfigured to attach to the mount 36 once the flapper has beenpositioned on the mount to thereby brace the flapper into position. Insome embodiments, a support plate or clip can include a ball retainer 26of a ball valve.

FIGS. 6A-6C illustrate one embodiment of a flapper 16. FIG. 6Aillustrates a top perspective view of the flapper, FIG. 6B illustrates abottom perspective view of the flapper, and FIG. 6C illustrates a sideview of the flapper. As illustrated, in some embodiments the flapper caninclude a sealing portion 48 and an attachment portion 40. The sealingportion can engage and seal against a flapper seat 18, as describedabove. The attachment portion can be used to position the flapper 16 ina floor drain valve 10, as described in more detail below. The sealingand attachment portions of the flapper can be joined by a flapper hinge22. Preferably, the flapper is formed as a single, unitary component,although in some embodiments the sealing and attachment portions can beformed separately and joined by a hinge 22.

In some embodiments, the sealing portion 48 of the flapper 16 caninclude one or more ridges, embossments, beams, or supports 19 on anupper side of the flapper. The flapper can also have one or moresupports 17 on a bottom side of the flapper. The supports can provideadditional structural integrity for the flapper so that it can helpretain its shape and retain a seal when the area below the flapper ispressurized. In some embodiments, the flapper can have a convex profileon its lower side, as visible in FIG. 6C, to help resist deformationfrom pressure beneath the flapper. Preferably, the flapper has anequilibrium position, as illustrated, in which the sealing portion 48and attachment portion 40 are at an angle α relative to each other. Thiscan help bias the flapper toward a closed position, as described in moredetail below. In some embodiments, the angle α can vary betweenapproximately 10 degrees and approximately 70 degrees. In someembodiments it can vary between approximately 20 degrees andapproximately 60 degrees. In some embodiments it can vary betweenapproximately 30 degree and 55 degrees. In some embodiments it can beapproximately 45 degrees.

In some embodiments, when the flapper 16 is positioned in a valve, suchas illustrated in FIG. 3 and FIG. 4, it can be configured and arrangedto pivot around a resilient hinge 22 into an open position to allowliquid to flow freely from the inlet and through the outlet of thehousing 14. The flapper can be disposed at an angle β within the housing14, such that the attachment portion 40 of the flapper is positionedcloser to the inlet, and the sealing portion 48 of the flapper ispositioned closer to the outlet. As depicted in FIG. 4, for example, thesealing portion 48 of the flapper 16 is positioned below the attachmentportion of the flapper. In some embodiments, the angle β can varybetween approximately 10 degrees and approximately 60 degrees. In someembodiments it can vary between approximately 20 degrees andapproximately 50 degrees. In some embodiments it can vary betweenapproximately 25 degree and 35 degrees. In some embodiments it can beapproximately 30 degrees.

The attachment portion 40 of the flapper is secured to a resilientflapper mount hinge 22. The flapper is constructed of a relatively rigidmaterial which is mounted with a resilient mount having a secureindexing ridge to positively position the flapper. The resilient hingebiases the flapper upwardly into sealing relationship with the flapperseat 18. The downwardly angled arrangement of the flapper 16 within thehousing 14 enables the flapper 16 to be easily opened (lowering thesealing end of the flapper from its normally closed position) due towater flow from the inlet to the outlet. The downwardly angledarrangement also prevents opening of the flapper due to gas flow fromthe outlet to the inlet.

The flapper can be made from a variety of materials, and is preferablymade from an elastomeric material. In some embodiments the flapper issufficiently rigid to resist back pressure but flexible. In someembodiments, the flapper can be constructed from a relatively rigidmaterial, such as various types of polymer materials, EPDM rubber,neoprene, silicone, etc. In some embodiments, the flapper can be formedfrom a material having a durometer between about 30 to 90. In someembodiments, the flapper can be formed from a material having adurometer between about 40 to 60. Preferably, the flapper is formed of amaterial that is sufficiently rigid to resist back pressures on theflapper, but sufficiently flexible and resilient to allow the hinge 22to rotate the flapper to and from the open and closed positions.

The attachment portion 40 of the flapper can have a variety of featuresto help ensure alignment of the flapper within a valve 10 wheninstalling the flapper and when the valve is in use. For example, insome embodiments the flapper can have one or more apertures 46 that canreceive a post or projection to help position the flapper. In someembodiments, the apertures can be slots. The flapper can also include anindexing ridge 42, which can be positioned in a corresponding channel.In some embodiments, the flapper can include a cutout 44, which can beused to fit the attachment portion 40 around components of a valve asnecessary. For example, in some embodiments the cutout can be positionedaround a pressure relief conduit 34. These various features and theirrelationship to other parts of a valve are described in more detailbelow.

FIGS. 7A-7C illustrate an alternate embodiment of a flapper 16. FIG. 7Aillustrates a top perspective view of the flapper, FIG. 7B illustrates abottom perspective view of the flapper, and FIG. 7C illustrates a sideview of the flapper. Many of the aspects can be the same as aspects ofthe flapper 16 discussed with respect to FIGS. 6A-6C, and where notdescribed herein similar numbering can be considered to refer to similarfeatures with similar functions. In some embodiments, a flapper can havevarying numbers of supports 19. As illustrated in FIG. 7A, in someembodiments a flapper can have three supports 19. FIG. 7A alsoillustrates an embodiment of a flapper 16 in which a cutout 44 extendsat least partially through the indexing ridge 42.

Although the flappers 16 are illustrated as generally round, they canhave a variety of shapes. In some embodiments, for example, the flapperscan be rectangular, circular, hexagonal, octagonal, or of other shapes.In some embodiments, the sealing portion 48, the attachment portion 40,and/or the hinge 22 can have multiple components. In some embodiments,for example, a flapper can include two substantially semicircularrelatively rigid flapper elements positioned side-by-side and attachedwith a resilient hinge each at an upper end thereof to a diametricallypositioned mounting structure. Each of the flapper elements can have aperipheral edge resiliently urged upwardly into sealing contact with aflapper seat 18 or a portion of a flapper seat. In some embodiments, aflapper can be a bi-valve, a duckbill valve, or other type of one-wayvalve. In some embodiments, a flapper 16 can be formed of overlappingwedges.

FIG. 8 illustrates a bottom perspective view of a housing 14 of a valve10. The housing can include a flapper mount 36 configured to receive theattachment portion 40 of a flapper. In some embodiments, a flapper mountcan include one more projections 37 configured to pass throughcorresponding apertures or slots on a flapper to help retain the flapperin position. In some embodiments, a flapper mount can include anindexing channel 38 configured to receive a corresponding indexing ridgeof a flapper. The indexing channel and indexing ridge can help properlyalign the flapper and also distribute forces exerted by back pressureupon the flapper to thereby help maintain the flapper in its positionwhen sealed against a valve seat. In some embodiments, a housing 14 caninclude at least a portion of a pressure relief conduit 34, and theflapper can include a cutout, described above, configured to fit aroundthe conduit.

FIG. 8 also illustrates a flapper seat 18, against which a flapper 16can seal when the flapper is in a closed position. Preferably, theflapper mount 36 is parallel with the plane of the flapper seat 18. Insome embodiments, the flapper mount can be at an angle relative to theplane of the flapper seat, but the angle is preferably less than theangle between the attachment portion 40 and sealing portion 48 of aflapper configured for use with the housing. Thus, when the attachmentportion is positioned on the flapper mount and held into place by asupport plate or clip 23 (illustrated in FIG. 1B), and the flapper 16tends toward its equilibrium position, the sealing portion 48 of theflapper can press against the flapper seat 18 to create a seal. In someembodiments, the flapper can be configured such that the seal is ofvarying strength, depending on the desired properties of the drain valve10. In some embodiments, the flapper can be configured such that thesealing portion 48 of the flapper is aligned with the flapper seat 18when the flapper is in an equilibrium position, and no seal is createdbetween the flapper and the flapper seat until the flapper experiences apressure on its bottom side.

The seal between the flapper 16 and the flapper seat 18 can help preventthe flow of noxious gases below the flapper from flowing past theflapper. The seal can also help prevent fluid from flowing upward, suchas during a storm event or during back pressure testing. If the flapperis expected to withstand particularly high pressure events, it can bemade thicker or with additional supports 17, 19 to help make sure thatthe flapper does not buckle against the pressure. When liquid flows uponthe upper surface of the flapper 16, however, the pressure of the liquidcan cause the flapper to angle away from the flapper seat 18 to therebyopen the valve 10, permitting passage of the liquid. Once the liquidflows past, the resilient hinge 22 can return the flapper toward itsequilibrium position, which can include resealing the flapper againstthe flapper seat.

In some embodiments, the housing 14 can have various features configuredto allow the housing to expand outward to seal the housing against agasket surrounding the housing and/or to help seal the gasket against adrain conduit 60. Outward expansion of the housing can also help thehousing and/or gasket engage the drain conduit so that the drain valve10 is not forced upwardly from pressure below it, such as in embodimentsin which a drain valve is designed to withstand back pressures (e.g.,during back pressure testing). In some embodiments, for example, anupper section 82 of the housing 14 can include a plurality of expandablesections 86 separated by slots 80. An insert can be inserted into theupper section which can expand the expandable sections 86 outward, whichcan in turn press against a gasket surrounding the housing. In someembodiments, the upper section 82 can have internal threading 87, and aninsert can be a bushing. In some embodiments, the housing 14 can be asingle piece or component, and in some embodiments the housing can beformed of multiple, connected pieces.

FIGS. 9A-9B illustrate one embodiment of a bushing 84 that can beinserted within an upper section 82 of the housing and expand thehousing 14. The bushing can have external threading 85 that can beconfigured to couple with the internal threading 87 of the housing. Insome embodiments, the threading of the bushing 84 and/or the internalthreading 87 of the housing can be tapered so that upon threadingbushing 84 farther into the upper portion 82 of the housing, thesegments 86 are forced farther outward to further tighten the drainvalve 10 into position within a drain conduit 60. In some embodiments,an outer diameter of at least a section of the bushing can increase froma bottom of the section to a top of the section. In some embodiments, aninner diameter of at least a portion of the housing can increase from abottom of the portion to a top of the portion.

In some embodiments, the bushing 84 can include a section 88 with anon-circular internal profile. This section can be used to receive atool, such as the tool 50 shown in FIG. 9A, to help tighten or loosenthe bushing within the housing 14. In some embodiments, the tool 50 canbe a single use tool that is sold attached to the bushing 84. Theconnection between the tool and bushing can be frangible and can beconfigured to break at a desired level of torque. Thus, the tool can berotated to tighten the bushing into the housing until the desired levelof torque is reached, at which point the tool can break off. The tool 50can be tightened with a square driver, such as a ½ inch driver, that canbe inserted into the center of the tool. In some embodiments, otherconnections are possible between the tool and a driver.

FIG. 10A illustrates a cross sectional view of one embodiment of a drainvalve 10 showing the presence of a ball valve 24 in a pressure reliefconduit 34. The ball valve 24 can have a ball valve seat 32 and a ballretainer 26 positioned at the bottom of the conduit, below the flapper.The ball retainer 26 is designed to retain a ball 27. The ball valve 24is configured to resist backward pressure and flow of fluids to test thedownstream area for leakage. The ball valve 24 is closed by the presenceof back ward flow of water and permits back pressure testing of thedownstream drain conduits.

The flapper 16 is constructed of a relatively rigid material such asvarious types of plastics well known in the art and is mounted with theelastomeric hinge 22. The ball valve 24 which is normally in an openposition rises to engage with the ball valve seat 32 and closes thepressure equalization conduit 34 when fluid flows upward thereby sealingthe floor drain valve to prevent the flow of fluid in a reversedirection. When the fluids push upwardly against the flapper 16, itpresses against the flapper seat 18 and forms a tight seal to preventthe fluid from moving upwardly past the flapper 16. Thus, whenever waterflows upon the upper surface of the flapper 16, the flapper 16 openspermitting passage of the water, and then reseal resiliently against theflapper seat 18 to prevent gases from the downstream drain conduits frompassing upwardly past the flapper 16, permitting pressure testing of thedownstream drain conduits. Thus, the second embodiment permits the flowdrain valve to provide with dual function such as preventing backflow ofgases and pressure testing the downstream drain conduits.

The outer housing 12 together with gasket 12 provides multiplepositioning rings and sealing rings that are contemplated to fit in thevarious drain conduit configurations encountered in the field.

In FIG. 10B there is shown a partial cross section of the gasketstructure utilized in the drain valve body within a drain conduit. Shelf15 serves to locate the gasket 12 upon a horizontal surface (not shown)of the drain conduit. At the lower zone 78 of gasket 12 a shelf 79 isprovided, to receive a corresponding surface of the valve body 10, andto provide additional sealing mechanisms, such as by integrally molded“O” ring 77. Upwardly directed pressure causes shelf 79 to seal againstthe horizontal surface of the drain conduit.

FIG. 11 shows a partial cross section of one embodiment of a gasketstructure that includes an inflatable membrane 72 that can be used tosecure the gasket (and drain valve 10) into position within a drain. Insome embodiments, an inflation valve 73 of the inflatable member can beaccessible from the flange or shelf 15 of the gasket. The gasket can beinserted into the drain valve with the membrane deflated, and themembrane can be inflated to secure the gasket in position. To remove thegasket, the membrane can be deflated. In some embodiments, a gasket caninclude sealing projections in addition to an inflatable membrane.

The terms “approximately”, “about”, and “substantially” as used hereinrepresent an amount or characteristic close to the stated amount orcharacteristic that still performs a desired function or achieves adesired result. For example, the terms “approximately”, “about”, and“substantially” may refer to an amount that is within less than 10% of,within less than 5% of, within less than 1% of, within less than 0.1%of, and within less than 0.01% of the stated amount or characteristic.

Additionally, the term “closed” when used with reference to a valvepreventing or blocking passage of fluid through the valve is usedbroadly and includes its ordinary and customary meaning. In certainembodiments, it means allowing within less than 1% of, within less than0.1% of, and/or within less than 0.01% of, and in certain embodiments 0%of the flow that would pass through the valve in the open positionduring anticipated operating conditions. In some embodiments, the termclosed when used with reference to preventing passage of fluid through avalve means that the valve allows some fluid passage at lower pressuresbut completely blocks fluid passage above a minimum pressure. Forexample, in some embodiments it can mean completely blocking fluidpassage above the minimum pressure of 0.2 psi, 0.5 psi, or 1.0 psi. Insome embodiments, it can mean completely blocking fluid passage atpressures above the minimum pressures and up to a maximum pressure of atleast 6 psi, 7 psi, 8 psi, or greater.

Although the foregoing description of the preferred embodiments hasshown, described and pointed out the fundamental novel features of theinvention, it will be understood that various omissions, substitutions,and changes in the form of the detail of the apparatus as illustrated aswell as the uses thereof, may be made by those skilled in the art,without departing from the spirit of the invention.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. Thus, appearances of the phrases “in one embodiment” or “inan embodiment” in various places throughout this specification are notnecessarily all referring to the same embodiment. Furthermore, theparticular features, structures or characteristics of any embodimentdescribed above may be combined in any suitable manner, as would beapparent to one of ordinary skill in the art from this disclosure, inone or more embodiments. For example, various embodiments of flappervalves described herein can be used with various housings, withembodiments that do not include a ball valve, with embodiments that doinclude a ball valve, etc. Similarly, as a further example, the variousgasket embodiments (including gaskets with sealing projections and/orinflatable membranes) can be used with the various flapper and valveembodiments.

Similarly, it should be appreciated that in the above description ofembodiments, various features of the inventions are sometimes groupedtogether in a single embodiment, figure, or description thereof for thepurpose of streamlining the disclosure and aiding in the understandingof one or more of the various inventive aspects. This method ofdisclosure, however, is not to be interpreted as reflecting an intentionthat any claim require more features than are expressly recited in thatclaim. Rather, as the following claims reflect, inventive aspects lie ina combination of fewer than all features of any single foregoingdisclosed embodiment. Thus, the claims following the DetailedDescription are hereby expressly incorporated into this DetailedDescription, with each claim standing on its own as a separateembodiment.

1. A floor drain valve comprising: a drain valve housing configured tofit within a drain conduit, the drain valve housing including an inlet,an outlet, and a valve seat; a flapper mounted within the housing andhaving a first side facing a first side of the valve and a second sidefacing a second side of the valve, the flapper biased toward a closedposition in which the first side of a sealing portion of the flapperengages with the valve seat to thereby block at least a portion ofbackflow through the drain housing, wherein the flapper is configuredsuch that a pressure on the first side of the flapper moves the flapperto an open position in which fluid can flow past the flapper; a pressureequalization conduit fluidly connecting a first side of the drain valveon the first side of the flapper with a second side of the drain valveon the second side of the flapper; a valve member within the pressureequalization conduit, the valve member configured to move from a closedposition that substantially blocks fluid transfer between the first andsecond sides of the drain valve to an open position when a pressure onthe second side of the drain valve exceeds a first defined pressure,thereby allowing the pressure on the second side of the drain valve tobleed into the first side of the drain valve.
 2. The floor drain valveof claim 1, wherein the valve member within the pressure equalizationconduit is configured to open when the pressure on the second side ofthe drain valve is greater than a pressure on the first side of thedrain valve such that the valve member allows equalization of pressurefrom the second side of the drain valve to the first side of the drainvalve.
 3. The floor drain valve of claim 1, further comprising a shieldconnected to the drain housing and configured to cover the pressureequalization conduit.
 4. The floor drain valve of claim 1, wherein thedrain valve housing is a monolithic housing.
 5. The floor drain valve ofclaim 1, wherein the flapper comprises an attachment portion and thehousing comprises a flapper mount configured to receive the attachmentportion.
 6. The floor drain valve of claim 5, wherein the flapperfurther comprises a resilient hinge connecting the attachment portion ofthe flapper and the sealing portion of the flapper, the resilient hingebiasing the flapper into the closed position.
 7. The floor drain valveof claim 6, wherein the flapper is monolithically formed.
 8. The floordrain valve of claim 1, further comprising a backflow valve in fluidcommunication with the pressure equalization conduit, the backflow valveconfigured to allow backflow of fluid through the pressure equalizationconduit below a second defined pressure and to substantially blockbackflow of fluid through the pressure equalization conduit above asecond defined pressure, wherein the second defined pressure is greaterthan the first defined pressure.
 9. The floor drain valve of claim 8,wherein the backflow valve is a ball valve.
 10. A floor drain valvecomprising: a drain valve housing comprising an inlet and an outlet; aone way valve positioned within the drain valve housing, the one wayvalve configured to restrict backflow through the drain housing whileallowing fluid to drain through the drain housing from the inlet to theoutlet in a first direction; a pressure equalization conduit fluidlyconnecting a first side of the one way valve a second side of one wayvalve; and a valve member configured to move from a closed position thatrestricts fluid transfer between the first and second sides of the oneway valve to an open position when a pressure on the second side of theone way valve exceeds a first defined pressure, thereby allowing thepressure on the second side of the one way valve to bleed into the firstside of the one way valve.
 11. The floor drain valve of claim 10,further comprising a shield configured to prevent fluid draining throughthe drain housing from blocking the valve member.
 12. The floor drainvalve of claim 10, wherein the one way valve comprises a sealingmembrane.
 13. The floor drain valve of claim 12, wherein the sealingmembrane is monolithic.
 14. The floor drain valve of claim 12, whereinthe sealing membrane comprises a resilient hinge configured to bias thesealing membrane into a position to restrict backflow through the drainhousing. 15.-41. (canceled)
 42. A method of draining a floor whilepreventing the backflow of gas comprising: positioning a relativelyrigid flapper within a cylindrical body such that a peripheral edge ofthe flapper adjacent an inlet of the cylindrical body is fixed with aresilient hinge to the cylindrical body, said resilient hinge biasingsaid flapper into sealing relationship with a sealing surface; andpermitting said flapper to rotate downwardly towards the outlet whenwater is present on an upper surface of said flapper.
 43. The method ofclaim 42, further comprising slidably engaging the cylindrical body intoa drain basin.
 44. The method of claim 43, wherein positioning theperipheral edge of the flapper adjacent an inlet of the cylindrical bodyincludes clamping the peripheral edge to a mounting portion of thecylindrical body.
 45. (canceled)
 46. The method of claim 42, furtherincluding the step of applying fluid pressure in the conduit below saidvalve to test said conduit for leaks.